Save yourself a few pounds and visit Avon Springs ?
http://www.fishingfly.co.uk/
Last time I visited the local smokery to drop off a fish (Thursday 24 May) another angler was delivering a catch of Dever fish that looked very nice indeed, including a good brown caught on a dry daddy. He did say that the fishery was crowded - in midweek.....
When I fished Avington fairly regularly in the 2002 to 2005 period I used to find that the fish, while certainly impressive, to their detriment were quite fatty when gutted and prepared for the table, or smoked. Rumoured to be a result of them being pushed hard on pellet in the stews.